The document discusses vital statistics, which are numerical records of life events like births, deaths, marriages, and divorces that can be used to study public health trends. Vital statistics are collected through civil registration systems and sample surveys. They provide data to evaluate health programs, plan for disease control, inform legislation and policymaking, and allow comparisons between populations. Important vital statistics include crude death rate, age-specific death rate, infant mortality rate, neonatal mortality rate, post-neonatal mortality rate, and maternal mortality rate.